New synthesis of (RS)‐carnitine chloride

A four‐step synthesis of (RS)‐carnitine chloride was developed using extremely mild reaction conditions and versatile intermediates. Crotyl chloride was converted to tert‐butyl 3‐butenoate using tert‐butyl alcohol and triethylamine in ether. Treatment of tert‐butyl 3‐butenoate with m‐chloroperbenzoic acid in chloroform afforded tert‐butyl 3,4‐epoxybutyrate. Reaction of this compound with trimethylamine hydrochloride in methanol, followed by mild acid hydrolysis of the tert‐butyl ester, afforded (RS)‐carnitine chloride.